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Changes of conductivity in patients with second- or third-degree atrioventricular block after pacemaker implantation
M Sumiyoshi1, Y Nakata, M Yasuda
1Department of Cardiology, Juntendo University School of Medicine Tokyo, Japan.
Insights
Most patients with complete atrioventricular (AV) block did not regain AV conductivity long-term after pacemaker implantation. Second-degree block, particularly His-ventricular (H-V) block, often progressed to complete AV block.
Area of Science:
- Cardiology
- Electrophysiology
Background:
- Atrioventricular (AV) block can necessitate pacemaker implantation.
- Understanding the long-term conductivity course post-implantation is crucial for patient management.
Purpose of the Study:
- To investigate the long-term changes in atrioventricular (AV) conductivity in patients with second- or third-degree AV block following pacemaker implantation.
Main Methods:
- A cohort of 54 patients with second- or third-degree AV block underwent 12-lead ECGs before and after a mean follow-up of 108 months.
- Comparison of AV block degree and QRS complex morphology between pre-implantation and follow-up ECGs.
Main Results:
- 85% of patients with complete AV block and 71% with second-degree AV block pre-implantation still had complete AV block long-term.
- Progression of AV block was observed primarily in patients with intra-His (BH) or infra-His (H-V) block.
- QRS complex changes occurred in 21% of patients, notably in the H-V block group (44%).
Conclusions:
- Complete AV block generally does not resolve, with most patients maintaining AV block long-term.
- Second-degree BH and H-V block show a tendency to progress to complete AV block over time.
Unlabelled:
The purpose of this study was to examine the long-term course of conductivity in patients with second- or third-degree atrioventricular (AV) block after pacemaker implantation. Fifty-four patients (30 males and 24 females, mean age 59.5 years) had a 12-lead electrocardiogram (ECG) recorded prior to pacemaker implantation and again after a follow-up of more than 5 years (mean 108 months). The degree of AV block and the morphology of the QRS complex in the two ECGs were compared. Twenty-eight (85%) of the 33 patients with complete AV block and 15 (71%) of the 21 patients with second-degree AV block before implantation showed complete AV block after the follow-up period. The progression of AV block was recognized only in patients with intra-His (BH) or infra-His (H-V) block. In 29 patients, escape QRS complexes were recorded in both ECGs. A change in the QRS complex was noted in 6 patients (21%), including 2 with new bundle branch block (BBB), 2 with wider BBB, 1 with new left axis deviation, and 1 with a change to another BBB. This change was particularly notable in the H-V block group (44%).
In Conclusion:
(1) Most patients with complete AV block did not recover AV conductivity after the long-term follow-up. (2) Second-degree BH and H-V block tended to progress to complete AV block.